How to update GUI in matlab App during a callback

Hello

Environement: matlab R2021b and R2021a, windows 10

I would like to change the color of a button during a callback in an Matlab App created with the App Designer.

% Button pushed function: LoadButton
function LoadButtonPushed(app, event)

set(app.LoadButton,'BackgroundColor',[1, 0, 0])%set color of the button to red
%... do things..
set(app.LoadButton,'BackgroundColor',[0, 1, 0])%set color of the button to green            

end

I see only the green button in the end, but not the red button while the callback function is running. It seems that there is something like a refresh or update, somthine like guidata in GUIDE is needed.

How do I update the user interface inbetween?

Many thanks and best wishes

Answer 1

[Bruno Luong]

Try to force refresh with drawnow

% Button pushed function: LoadButton
function LoadButtonPushed(app, event)

set(app.LoadButton,'BackgroundColor',[1, 0, 0])%set color of the button to red
drawnow
%... do things..
set(app.LoadButton,'BackgroundColor',[0, 1, 0])%set color of the button to green            
drawnow
end

[Hiro Yoshino]

Did this help you out? I doubt....

[Bruno Luong]

@Hiro I let you test attached file if you have any doubt

[Timo]

Works perfectly. Many thanks Bruno!

[Hiro Yoshino]

Wow it's great ☺

Answer 2

[Hiro Yoshino]

Please see here: https://www.mathworks.com/help/matlab/creating_guis/write-callbacks-for-gui-in-app-designer.html

the changes made by valuChanged callback functions are reflected later. If you want to see the changes dinamically, you should use valuChanging callback functions.